Magnetic spiral machine and preparation method and application thereof

Abstract

The invention relates to a magnetic spiral machine. The magnetic spiral machine comprises a spiral magnetic inner core, nano thorns distributed on the spiral magnetic inner core, a nano metal film covering the spiral magnetic inner core and the nano thorns, and a Raman tag modified on the nano metal film. The invention further provides a method for preparing the magnetic spiral machine, application of the magnetic spiral machine to acquisition of signals in a living body and application of the magnetic spiral machine to preparation of drugs for treating tumors. According to the technical scheme, the killing accuracy and killing capability of the SERS reagent are improved.

Description

Technical Field

[0001] The present invention relates to the field of nanomaterials, and in particular, to a magnetic spiral machine, a method for preparing the magnetic spiral machine, and the use of the magnetic spiral machine in signal collection in a living body and the use of the magnetic spiral machine in preparing drugs for treating tumors. Background Art

[0002] Biological research and early diagnosis of diseases require highly sensitive and specific detection methods for biomolecules. Life processes involve dynamic changes in the conformation, distribution, and interactions of various biomolecules in time and space, while the generation and evolution of diseases usually involve excess, deficiency, or dysfunction of biomolecules. Monitoring these dynamic changes related to biomolecules and changes in the microenvironment within biological systems is crucial to better understand the evolutionary mechanisms of life processes and various diseases, as well as to establish reliable and highly sensitive diagnostic methods.

[0003] Various techniques such as nuclear magnetic resonance, mass spectrometry, electrochemistry and cryo-electron microscopy have provided a wealth of information for the development of biomedical and bioanalytical research. However, they are limited in spatial resolution or the study of single cells in vivo. In contrast, optical techniques, especially fluorescence microscopy, are by far the most important techniques for studying life processes, especially at the single-cell level. Fluorescence microscopy can provide high-contrast images with rich information about biological structure and function through appropriately modified fluorescent dyes. The development of confocal microscopy, total internal reflection fluorescence microscopy and super-resolution fluorescence microscopy has promoted our comprehensive and detailed understanding of biological systems. On the other hand, unlike fluorescence microscopy that relies on external dyes, Raman spectroscopy relies on inelastic light scattering of the sample itself. Raman spectra contain inherent characteristic vibration information determined by the chemical composition, symmetry and environmental factors of the sample. Therefore, Raman spectroscopy has been successfully used to determine chemical composition, molecular structure, conformation and molecular interactions. Raman spectroscopy can use light from ultraviolet to near-infrared as an excitation source with high spatial resolution. In addition, the Raman signal of water is very weak, so this technique can be applied to aqueous solution systems. However, Raman scattering has low sensitivity, which limits its widespread application in the biomedical field.

[0004] On rough Ag metal surfaces, the observation of surface enhanced Raman scattering (SERS) phenomena has significantly improved the detection sensitivity of Raman spectroscopy. The million-fold signal enhancement can observe the signal of a single layer of material on the metal surface, and has achieved the sensitivity of single-molecule detection. SERS has important applications in chemistry, materials science, analytical science, surface science, biomedical research and other fields. Compared with traditional bioanalysis methods, SERS has special advantages in bioanalysis: (1) SERS has ultra-high surface sensitivity even down to the single-molecule level; (2) SERS signals can reflect the inherent molecular fingerprint information of biological systems; (3) SERS is resistant to photobleaching and photodegradation compared to fluorescence, and is suitable for long-term monitoring; (4) The bandwidth of the SERS peak is usually narrow, 10-100 times narrower than the fluorescence emission of organic dyes or quantum dots; (5) SERS can conveniently perform multiple detections with single-wavelength excitation; (6) SERS-active nanostructures can be designed with different sizes, shapes and coatings for different detection purposes. As a result, many impressive developments have been achieved in SERS and its biomedical and bioanalytical applications, and have been successfully used to detect biomolecules, pathogens, cancer cells, in vivo tumor imaging, etc.

[0005] CN201810386181.4 discloses the use of multifunctional anticancer aptamer AS1411 as a template to generate protected silver nanoclusters, which are assembled and composited with modified graphene quantum dots (GOD), and then adsorbed with anticancer drugs with aromatic ring structures through π-π interaction to construct diagnostic and therapeutic reagents with SERS / fluorescence dual-modality targeted tumor cell imaging. CN201610024992.0 discloses the preparation of star-shaped gold nanoparticles with strong absorption properties for near-infrared light, followed by modification of Raman molecules on the surface of gold nanoparticles, and then further binding to polypeptides that can specifically bind to tumor cells. Thus, the probe has multiple functions and can implement targeted tumors, SERS imaging, and photothermal killing.

[0006] However, the accuracy and ability of existing SERS reagents to kill tumor cells still need to be improved. Summary of the invention

[0007] The purpose of the present invention is to improve the killing accuracy and killing ability of the SERS reagent.

[0008] In order to achieve the above objectives, the present invention provides a magnetic spiral machine, which includes a spiral magnetic core, nanothorns distributed on the spiral magnetic core, a nanometal film covering the spiral magnetic core and the nanothorns, and a Raman tag modified on the nanometal film.

[0009] Optionally, the spiral magnetic core contains magnetic particles, and the magnetic particles are Fe4O3 nanoparticles.

[0010] Optionally, the spiral magnetic core further contains a polymerized negative photoresist.

[0011] Optionally, the nanothorns contain a polymerized negative photoresist.

[0012] Optionally, the metal film is a nano-gold film obtained by sputtering.

[0013] Optionally, the Raman tag is ferric ferrocyanide.

[0014] Optionally, the size of the spiral magnetic core is 100-300 μm, and the size of the nanothorns is 100-700 nm.

[0015] On the other hand, the present invention also provides a method for preparing a magnetic spiral machine, which comprises: S1, laser direct writing of a negative photoresist doped with magnetic nanoparticles, and batch printing to obtain a spiral magnetic core precursor having magnetic properties and covered with nanothorns on the surface; S2, removing unpolymerized negative photoresist with a developer to obtain a spiral magnetic core; S3, using ion sputtering to deposit a nanometal film on the surface of the spiral magnetic core; S4, modifying a Raman tag on the nanometal film.

[0016] The present invention also provides the use of the magnetic spiral machine as described above in signal acquisition in a living body, wherein the living body includes at least one of an isolated organ, a cell, a tissue and a living body.

[0017] The present invention also provides the use of the magnetic spiral machine as described above in preparing drugs for treating tumors.

[0018] Through the above technical scheme, the present invention improves the killing accuracy and killing ability of SERS reagents. In the present invention, the nano needle-like structures densely distributed on the surface of the spiral machine, after gold modification, the gaps of the needle-like structures will produce a strong Raman enhancement effect. Therefore, high-density Raman hotspots are formed on the surface of the spiral machine, which can not only enhance the Raman signal intensity, but also improve the stability and reliability of Raman detection; the nano needle-like structures on the surface of the spiral machine have a high specific surface area and are easier to connect with the object to be detected. At the same time, the needle-like structure can be anchored with the tissue to achieve accurate biological signal detection; traditional Raman tags usually show multiple spectral bands in the fingerprint area, and these spectral bands usually overlap with the main endogenous biological molecule spectral bands. The surface-modified Prussian blue shell has a high-intensity narrow peak width Raman peak only in the silent area of ​​the biological Raman signal, making the spiral machine easy to image in vivo and will not interfere with the detection of other biological signals; compared with the traditional Raman enhanced detection platform or Raman detection probe, the magnetic spiral SERS machine has controlled movement ability and does not need to rely on the internal circulation system or endocytosis for biological detection. The spiral motor can achieve detection of biological molecules and environments in hard-to-reach areas while ensuring a strong Raman enhancement effect; clustered spiral machines have higher execution efficiency, and the SERS machine that focuses the magnetic field can further enhance the Raman enhancement effect of nanotargets on the object being measured.

[0019] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0020] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0021] The present invention provides a magnetic spiral machine, which comprises a spiral magnetic core, nanothorns distributed on the spiral magnetic core, a nanometal film covering the spiral magnetic core and the nanothorns, and a Raman label modified on the nanometal film.

[0022] The present invention uses two-photon laser direct writing technology to batch print out magnetic micron spiral motor arrays with nano-needle structures on the surface, and then ion sputters a gold layer on the surface of the needle structure as a Raman enhancement substrate and improves its biocompatibility. After a chemical reaction, a layer of Prussian blue is modified on the surface of the gold layer as a Raman imaging label in the tissue to track the distribution of the machine cluster. The spiral SERS machine dispersed in PBS is injected intravenously into the ex vivo tissue / living body, and under the control of an external magnetic field, it performs intravascular and intracavitary movement and biological detection. After detecting the tumor site, the lesion area can be mechanically damaged by spiral drilling.

[0023] Optionally, the spiral magnetic core contains magnetic particles, and the magnetic particles are Fe4O3 nanoparticles.

[0024] Optionally, the spiral magnetic core further contains a polymerized negative photoresist.

[0025] Optionally, the nanothorns contain a polymerized negative photoresist.

[0026] Optionally, the metal film is a nano-gold film obtained by sputtering.

[0027] Optionally, the Raman label is ferric ferrocyanide (Fe4[Fe(CN)6]3, Prussian blue).

[0028] Optionally, the size of the spiral magnetic core may be 50-500 μm, preferably 100-300 μm, and the size of the nanothorns may be 50-1000 nm, preferably 100-700 nm.

[0029] On the other hand, the present invention also provides a method for preparing a magnetic spiral machine, which comprises: S1, laser direct writing of a negative photoresist doped with magnetic nanoparticles, and batch printing to obtain a spiral magnetic core precursor having magnetic properties and covered with nanothorns on the surface; S2, removing unpolymerized negative photoresist with a developer to obtain a spiral magnetic core; S3, using ion sputtering to deposit a nanometal film on the surface of the spiral magnetic core; S4, modifying a Raman tag on the nanometal film.

[0030] Wherein, a negative photoresist doped with Fe4O3 nanoparticles (SU-8 negative photoresist or IP-L negative photoresist) can be used. Wherein, the shape and size of the spiral magnetic core precursor and the nanothorn can be obtained by laser direct writing, for example, the parameters of the laser direct writing can be set so that the size of the spiral magnetic core can be 50-500μm, preferably 100-300μm, and the size of the nanothorn can be 50-1000nm, preferably 100-700nm.

[0031] The present invention also provides the use of the magnetic spiral machine as described above in signal acquisition in a living body, wherein the living body includes at least one of an isolated organ, a cell, a tissue and a living body.

[0032] The present invention also provides the use of the magnetic spiral machine as described above in preparing drugs for treating tumors.

[0033] The present invention is further described in detail below by way of examples.

[0034] Example 1

[0035] Preparation and characterization of Raman tag-modified magnetic helical SERS machine clusters.

[0036] The spiral micromachines were written by a laser direct writer using a negative photoresist (SU-8 or IP-L) doped with Fe4O3 nanoparticles, and the surface of the spiral structure was densely distributed with nanothorn-like structures. Subsequently, the unpolymerized photoresist was removed by a developer to obtain an array of spiral machines. After development and drying, an Au nanolayer was deposited on the surface of the polymer spiral machine using ion sputtering for subsequent Raman detection functionalization and biocompatibility improvement. The spiral machine array with a deposited gold layer was treated with K3[Fe(CN)6](0.5mM) for 5 minutes, and the gold layer surface was covered with CN. At the same time, it was treated with K4[Fe(CN)6](0.1mM) and FeCl3(0.1mM) to form a CN-bridged Prussian blue (ferric ferrocyanide (Fe4[Fe(CN)6]3)-coated shell as a Raman tag. Finally, the Raman tag-modified magnetic spiral SERS machine array was dispersed in deionized water / PBS by ultrasound.

[0037] After preparation, the spiral structure and surface needle morphology of the machine were observed by scanning electron microscopy and transmission electron microscopy, the elemental composition and distribution were characterized by EDS energy spectrum, the phase composition of the sample was determined by XRD, the hysteresis loop of the sample was measured by PPMS, the absorbance spectrum of the sample was tested by UV-visible spectrophotometer, and the biocompatibility of the sample was investigated by co-culture experiment.

[0038] Example 2

[0039] Controlled motion of magnetic helical machine clusters and studies of motion in ex vivo tissues

[0040] The prepared magnetic spiral SERS machine was dispersed in deionized water / PBS for motion study. First, an external gradient magnetic field and a rotating magnetic field were applied to a single spiral machine for motion control, and the influence of other factors (spiral machine size, magnetic field setting parameters, and environmental physical and chemical properties) on the kinematic parameters were analyzed. Secondly, the aggregation, dispersion, and unified motion of the magnetic spiral SERS machine cluster were achieved through oscillating fields, conical fields, gradient fields, rotating fields, and their combinations. The effect of cluster motion on the environmental flow field and the effectiveness of motion in in vitro tissues (such as blood vessels and cavities) were simulated and analyzed, and the drilling effect and dynamic analysis of spiral machine clusters on tissues such as tube walls and cavity walls were explored.

[0041] Example 3

[0042] Raman signal detection and Raman imaging of magnetic spiral SERS machine.

[0043] Through confocal Raman microscopy, the Raman enhancement effect of SERS machine clusters on different biological molecules and dyes, the relationship between signal multiplication and the concentration of the tested object, and the reliability and stability of the test results were studied. In addition, since Prussian blue has a high-intensity and narrow-width Raman peak only in the silent area of ​​biological Raman signals, the Raman signal enhancement effect of the gold layer on the Prussian blue shell is used to achieve in-tissue / in-vivo imaging of the magnetic spiral SERS machine cluster without affecting the detection of biological molecules by the SERS machine.

[0044] Example 4

[0045] In vitro / in vivo signal acquisition from magnetic helical SERS machine clusters.

[0046] The magnetic spiral SERS machine is injected into the in vitro organ / live mouse through intravenous injection, and the machine cluster is controlled to move under the control of an external magnetic field. The machine in the tissue is imaged by a confocal Raman microscope, and the distribution of the machine is tracked dynamically. At the same time, at the detection site, the machine community is controlled to aggregate, and the Raman spectrum is obtained after anchoring to the biological molecules in the environment or the surface of the tissue, and the physical and chemical properties are analyzed and the pathological conditions are detected. After the detection is completed, the magnetic field mode is changed to disperse the SERS machine cluster, and the next site is targeted to carry out the biochemical detection task. After determining the tumor site, the machine cluster is controlled to drill the tumor and apply mechanical killing.

[0047] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0048] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0049] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A magnetic screw machine, characterized in that: The magnetic spiral machine comprises a spiral magnetic core, nanothorns distributed on the spiral magnetic core, a nanometal film covering the spiral magnetic core and the nanothorns, and a Raman tag modified on the nanometal film.

2. The magnetic screw machine according to claim 1, wherein: The spiral magnetic core contains magnetic particles, and the magnetic particles are Fe4O3 nanoparticles.

3. The magnetic screw machine according to claim 2, wherein: The helical magnetic core also contains a polymerized negative photoresist.

4. The magnetic screw machine according to claim 1, wherein: The nanothorns contain a polymerized negative photoresist.

5. The magnetic screw machine according to claim 1, wherein: The metal film is a nano-gold film obtained by sputtering.

6. The magnetic screw machine according to claim 1, wherein: The Raman tag is ferric ferrocyanide.

7. The magnetic screw machine according to claim 1, wherein: The size of the spiral magnetic core is 100-300 μm, and the size of the nanothorn is 100-700 nm.

8. A method for preparing a magnetic spiral machine, characterized in that: The method includes: S1. Directly writing the negative photoresist doped with magnetic nanoparticles by laser to batch print and obtain a magnetic spiral magnetic core precursor with nanothorns on the surface; S2, removing the unpolymerized negative photoresist by a developer to obtain a spiral magnetic core; S3, depositing a nano-metal film on the surface of the spiral magnetic core using ion sputtering; S4, modifying a Raman tag on the nanometal film.

9. Use of the magnetic spiral machine according to any one of claims 1 to 7 in signal collection in a living body, wherein: The organism includes at least one of an isolated organ, a cell, a tissue and a living body.

10. Use of the magnetic spiral machine according to any one of claims 1 to 7 in the preparation of drugs for treating tumors.